一、MyBatis 是一款优秀的持久层框架，它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息，将接口和 Java 的 POJOs(Plain Old Java Objects,普通的 Java对象)映射成数据库中的记录。相信很多人在使用mybatis的时候都有自己的感受吧，mybatis的框架使用很好的提高了我们自身的开发效率，和sql编写能力。为了简化编写和配置过程，这里我介绍spring-boot和mybatis的二种整合方式。
二、我这里为了简化项目，将两种方式写在一起的，下面我会单独介绍相关的配置。首先需要的jar包（pom.xml）
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.troy</groupId> <artifactId>springboot_mybatis</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.6.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>1.5.6.RELEASE</version> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.9</version> </dependency> </dependencies> </project>
三、目录结构
四、application.yml配置
server: port: 8080 spring: datasource: driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/model?useUnicode=true&characterEncoding=utf8 username: root password: root mybatis: mapper-locations: classpath:/mapper/*
五、第一种方式：采用@mapper的注解方式来实现数据库的访问
1、controller层
@RestController @RequestMapping(value = "/api/login") public class UserController { @Autowired private UserService userService; @RequestMapping(value = "/init") public String init() { return "hello world"; } @RequestMapping(value = "/findAll") public List<Map<String,Object>> findAll() { List<Map<String,Object>> list = userService.findAllMapper(); return list; } @RequestMapping(value = "/findById") public Map<String,Object> findById() { Long id = 1L; Map<String,Object> map = userService.findByIdMapper(id); return map; } }
2、service层
1）接口
public interface UserService { public List<Map<String,Object>> findAllMapper(); public Map<String,Object> findByIdMapper(Long id); }
2）实现类
@Service @Transactional public class UserServiceImpl implements UserService { @Autowired private UserMapper userMapper; @Override public List<Map<String, Object>> findAllMapper() { return userMapper.findAll(); } @Override public Map<String, Object> findByIdMapper(Long id) { return userMapper.findById(id); } }
3、mapper层
@Mapper @Repository public interface UserMapper { @Select(value = "select * from user") public List<Map<String,Object>> findAll(); @Select(value = "select * from user where id=#{id}") public Map<String,Object> findById(Long id); }
六、第二种方式：采用xml配置文件的方式
1、controller层
@RestController @RequestMapping(value = "/api/login") public class UserController { @Autowired private UserService userService; @RequestMapping(value = "/init") public String init() { return "hello world"; } @RequestMapping(value = "/findAll") public List<Map<String,Object>> findAll() { return userService.findAll(); } @RequestMapping(value = "/findById") public Map<String,Object> findById() { Long id = 1L; return userService.findById(id); } }
2、service层
1）接口
public interface UserService { public List<Map<String,Object>> findAll(); public Map<String,Object> findById(Long id); }
2）实现类
@Service @Transactional public class UserServiceImpl implements UserService { @Autowired private UserDao userDao; @Override public List<Map<String,Object>> findAll(){ return userDao.findAll(); } @Override public Map<String, Object> findById(Long id) { return userDao.findById(id); } }
3、dao层
1）接口
@Repository public interface UserDao { public List<Map<String,Object>> findAll(); public Map<String,Object> findById(Long id); }
2）实现类
@Repository public class UserDaoImpl implements UserDao{ @Autowired private SqlSessionTemplate sqlSession; @Override public List<Map<String, Object>> findAll() { return sqlSession.selectList("user.findAll"); } @Override public Map<String, Object> findById(Long id) { Map<String,Object> map = new HashMap<String,Object>(); map.put("id",id); return sqlSession.selectOne("user.findById",map); } }
4、userMapper.xml配置文件
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd"> <mapper namespace="user"> <select id="findAll" resultType="java.util.Map"> select * from user </select> <select id="findById" parameterType="java.util.Map" resultType="java.util.Map"> select * from user where id=#{id} </select> </mapper>
5、application.yml里面配置
mybatis:
mapper-locations: classpath:/mapper/*
七、总结：总体来说两种使用方式都是很不错的，注解的方式在使用上面很方便，也方便管理。xml配置文件的方式在使用上面更灵活，针对于sql量比较大的方式处理比较合理。在会涉及逻辑判断的时候，xml的方式使用就会体现的更加灵活。
